documentation organization for plugins that match specific backends

[agup006]

When we look at Fluent Bit documentation we have a few output destinations that are derivatives of HTTP such as Observe and upcoming with Dynatrace

These specific examples are great for users to understand how to use those specific solutions though they are not unique plugins linked to "plugin_id / code".

My proposal would be to keep input / filters / outputs as specific pages and then have example outputs as sub sections. For example for table of contents it would be the following where Dynatrace and Observe are sub bullets

Data Pipeline

• Outputs
  • HTTP
    • Dynatrace
    • Observe

cc: @edsiper @hans-lougas-dt